Zero weight battery charger for hybrid electric vehicles

ABSTRACT

A propulsion system for a hybrid electric vehicle comprises a traction motor having first and second stator windings; a power source having a DC power output coupled to the first windings; a battery having a DC power output coupled to the second windings; and a controller to independently control: (i) a first power level output at the first DC power output, and (ii) a second power level of motive power output by the traction motor; wherein responsive to a signal to set the second power level less than full capacity of the traction motor, the controller provides a power difference between the first and second power levels from the second windings to the battery.

DESCRIPTION OF RELATED ART

The disclosed technology relates to hybrid electric vehicles.

SUMMARY

In general, one aspect disclosed features an propulsion system for ahybrid electric vehicle, comprising: a traction motor having firststator windings and second stator windings; a power source having afirst direct current (DC) power output, the power source comprising agenerator; a battery having a second DC power output; a first inverterelectrically coupled between the first DC power output of the powersource and the first stator windings; a second inverter electricallycoupled between the second DC power output of the battery and the secondstator windings; and a controller configured to independently control:(i) a first power level of electric power output at the power output ofthe power source, and (ii) a second power level of motive power outputby the traction motor; wherein responsive to receiving a signal to setthe second power level at less than a full capacity of the tractionmotor, the controller is configured to provide a power differencebetween the first power level and the second power level from the secondstator windings through the second inverter to the battery; and whereinresponsive to the power difference between the first power level and thesecond power level exceeding a capacity of the battery to absorb power,the controller is configured to reduce the first power level of electricpower output at the power output of the generator.

Embodiments of the propulsion system may include one or more of thefollowing features. Some embodiments comprise a control interface,wherein the controller is further configured to independently controlthe first power level and the second power level responsive to signalsreceived from the control interface. In some embodiments, the secondinverter is a four-quadrant inverter. In some embodiments, the powersource comprises: an engine having a mechanical power output, whereinthe generator has (i) an electrical power output and (ii) a mechanicalpower input, the mechanical power input mechanically coupled to themechanical power output of the engine; and a rectifier having (i) anelectrical power input electrically coupled to the electrical poweroutput of the generator and (ii) an electrical power output electricallycoupled to the DC power output of the power source. In some embodiments,the engine is a combustion engine. In some embodiments, the hybridelectric vehicle is an aircraft. Some embodiments comprise avariable-pitch propeller; and a governor configured to control a pitchof the variable-pitch propeller; wherein the controller is furtherconfigured to control the governor responsive to signals received fromthe control interface. In some embodiments, the hybrid electric vehicleis an automobile.

In general, one aspect disclosed features a propulsion system for ahybrid electric vehicle, further comprising: a traction motor havingfirst stator windings and second stator windings; a power source havinga first direct current (DC) power output, the power source comprising agenerator; a battery having a second DC power output; a first inverterelectrically coupled between the first DC power output of the powersource and the first stator windings; a second inverter electricallycoupled between the second DC power output of the battery and the secondstator windings; one or more hardware processors; and a non-transitorymachine-readable storage medium encoded with instructions executable bythe hardware processor to perform operations comprising: responsive toreceiving signals from a control interface, independently controlling:(i) a first power level of electric power output at the power output ofthe power source, and (ii) a second power level of motive power outputby the traction motor; responsive to receiving a signal to set thesecond power level at less than a full capacity of the traction motor,providing a power difference between the first power level and thesecond power level from the second stator windings through the secondinverter to the battery; and responsive to the power difference betweenthe first power level and the second power level exceeding a capacity ofthe battery to absorb power, reducing the first power level of electricpower output at the power output of the generator.

Embodiments of the propulsion system may include one or more of thefollowing features. Some embodiments comprise a control interface,wherein the controller is further configured to independently controlthe first power level and the second power level responsive to signalsreceived from the control interface. In some embodiments, the secondinverter is a four-quadrant inverter. In some embodiments, the powersource comprises: an engine having a mechanical power output, whereinthe generator has (i) an electrical power output and (ii) a mechanicalpower input, the mechanical power input mechanically coupled to themechanical power output of the engine; and a rectifier having (i) anelectrical power input electrically coupled to the electrical poweroutput of the generator and (ii) an electrical power output electricallycoupled to the DC power output of the power source. In some embodiments,the engine is a combustion engine. In some embodiments, the hybridelectric vehicle is an aircraft. Some embodiments comprise avariable-pitch propeller; and a governor configured to control a pitchof the variable-pitch propeller; wherein the controller is furtherconfigured to control the governor responsive to signals received fromthe control interface. In some embodiments, the hybrid electric vehicleis an automobile.

In general, one aspect disclosed features a non-transitorymachine-readable storage medium encoded with instructions executable bya hardware processor of a computing component, the machine-readablestorage medium comprising instructions to cause the hardware processorto perform operations comprising: responsive to receiving signals from acontrol interface of a hybrid electric vehicle, independentlycontrolling: (i) a first power level of electric power output at adirect current (DC) power output of a power source of the hybridelectric vehicle, the power source electrically coupled by a firstinverter to first stator windings of a traction motor of the hybridelectric vehicle, the power source comprising a generator, and (ii) asecond power level of motive power output by the traction motor;responsive to receiving a signal to set the second power level at lessthan a full capacity of the traction motor, providing a power differencebetween the first power level and the second power level from secondstator windings of the traction motor through a second inverter to abattery of the hybrid electric vehicle; and responsive to the powerdifference between the first power level and the second power levelexceeding a capacity of the battery to absorb power, reducing the firstpower level of electric power output at the power output of a generatorof the hybrid electric vehicle.

Embodiments of the non-transitory machine-readable storage medium mayinclude one or more of the following features. In some embodiments, thehybrid electric vehicle is an aircraft. In some embodiments, theoperations further comprise: responsive to the signals received from thecontrol interface, controlling a governor configured to control a pitchof a variable-pitch propeller of the aircraft. In some embodiments, thehybrid electric vehicle is an automobile.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure, in accordance with one or more variousembodiments, is described in detail with reference to the followingfigures. The figures are provided for purposes of illustration only andmerely depict typical or example embodiments.

FIG. 1 illustrates a prior art independent parallel hybrid electricaircraft architecture.

FIG. 2 illustrates a prior art integrated parallel hybrid electricaircraft architecture.

FIG. 3 illustrates a hybrid electric aircraft propulsion system having aseries hybrid electric architecture according to some embodiments of thedisclosed technologies.

FIG. 4 illustrates a hybrid electric automobile propulsion system havinga series hybrid electric architecture according to some embodiments ofthe disclosed technologies.

FIG. 5 is a flowchart illustrating a process for controlling apropulsion system of a hybrid electric vehicle according to someembodiments of the disclosed technologies.

FIG. 6 is an example computing component that may be used to implementvarious features of embodiments described in the present disclosure.

The figures are not exhaustive and do not limit the present disclosureto the precise form disclosed.

DETAILED DESCRIPTION

Hybrid electric aircraft employ both combustion and electric power todrive the propulsion system. These aircraft have several significantadvantages over typical combustion-powered aircraft. For example, theemissions (especially on takeoff) and noise pollution of a hybridelectric aircraft are significantly reduced compared to acombustion-powered aircraft.

In due course it is expected that most if not all airports will beequipped with charging infrastructure for charging the batteries ofelectric and hybrid electric aircraft. But until this occurs there is aneed for an on-board battery charging capability. Current solutionsfeature a separate on-board battery charger, with its attendant costsand additional weight. A typical on-board charger weighs approximatelyTBD pounds per kilowatt of charging capacity. The addition of such acharger therefore reduces the payload capacity of the aircraft.Especially in smaller aircraft, this represents a significant drawback.

Several hybrid electric aircraft architectures exist. FIG. 1 illustratesa prior art independent hybrid electric aircraft architecture 100. Thisarchitecture features two independent electric and combustion powertrains, each driving a separate propeller. The electric power trainincludes a battery 102, an inverter 104, a motor 106 powered by thebattery 102, and a first propeller 116A driven by the motor 106. Thecombustion power train includes a combustion engine 108 driving a secondpropeller 116B. The independent hybrid electric aircraft architecture100 features an efficient method of connecting the power produced bycombustion to the propeller. However, this architecture requires aground charging infrastructure to charge the battery 102.

FIG. 2 illustrates a prior art integrated parallel hybrid electricaircraft architecture 200. This architecture features a single powertrain that includes a battery 202, an inverter 204, a motor 206 poweredby the battery 202, a combustion engine 208, and a single propeller 216driven by the motor 206 and the combustion engine 208. Like theindependent hybrid electric aircraft architecture 100, the integratedparallel hybrid electric aircraft architecture 200 features an efficientmethod of connecting the power produced by combustion to the propeller.And like the independent hybrid electric aircraft architecture 100, theintegrated parallel hybrid electric aircraft architecture 200 requires aground charging infrastructure to charge the battery 102. The integratedparallel hybrid electric aircraft architecture 200 is also moremechanically challenging to fabricate.

FIG. 3 illustrates a hybrid electric aircraft propulsion system 300having a series hybrid electric architecture according to someembodiments of the disclosed technologies. While the disclosedtechnologies are described with reference to hybrid electric aircraft,It should be understood by those skilled in the relevant arts that thesetechnologies may be applied to any hybrid electric vehicle or vessel.

Referring to FIG. 3 , the architecture 300 may feature a traction motor306 having at least two sets of independent stator windings 320A,B. Anelectric power train 330 may drive one set of stator windings 320A. Apower source in the form of a combustion power train 340 may drive theother set of stator windings 320B. In other embodiments, other powersources may drive stator windings 320B. Either or both of the statorwindings 320 may cooperate with rotating magnets fixed onto a propellershaft 318, to create torque and thereby turn one or more propellers 316of the aircraft. The rotating magnets may be permanent magnets orelectro-magnets.

The combustion power train 340 may include a combustion engine 308having a mechanical power output to drive a generator 310 having an ACpower output. The combustion power train 340 may include a rectifier 312that converts the AC output of the generator 310 to DC for transmissionover a first DC bus 324. The combustion power train 340 may include aninverter 314 to convert the DC power to AC for driving the statorwinding 320B. The electric power train 330 may include a battery 302having a direct current (DC) power output that provides DC power fortransmission over a second DC bus 322. The electric power train 330 mayinclude an inverter 304 to convert the DC power to alternating current(AC) for driving the stator winding 320A.

The architecture 300 may include a controller 350 to control theoperation of components of the propulsion system 300 in accordance withcommands or control signals received from control interface 360. Throughthe control interface 360 and the controller 350, an operator mayindependently control (i) a first power level of electric power outputat the power output of the combustion power train 340, and (ii) a secondpower level of motive power output by the traction motor 306. Thecontroller 350 may control the combustion power train 340 by controllingone or more of the battery 302, the combustion engine 308, the generator310, the rectifier 312, and the inverters 304 and 314, as indicated bythe broken lines in FIG. 3 . When the propeller 316 is a variable-pitchpropeller, the controller may control a governor 326 of the propeller316. When the propeller 316 is a fixed-pitch propeller, no governor 326is needed.

While the combustion power train 340 typically has power flow in onlyone direction, the electric power train 330 has bidirectional powerflow. The rotation of the magnets on the shaft 318 of the motor 306 mayinduce an AC voltage in the windings 320A, and the inverter 304 mayconvert that AC voltage into a DC voltage to charge the battery 302 overthe second DC bus 322. In some embodiments, the inverter 304 may beimplemented as a four-quadrant inverter or a similar inverter to enablethis bidirectional operation.

In some embodiments, the number of turns may differ between the two setsof stator windings 320A,B. These embodiments may allow the differentpower trains 330, 340 to operate at different voltages, and may provideadvantages in controlling the charging of the battery 302 from the motor306.

As noted above, the disclosed technologies may be applied to anyelectric vehicle or vessel. FIG. 4 illustrates a hybrid electricautomobile propulsion system 400 having a series hybrid electricarchitecture according to some embodiments of the disclosedtechnologies.

Referring to FIG. 4 , the architecture 400 may features a traction motor406 having at least two sets of independent stator windings 420A,B. Anelectric power train 430 may drive one set of stator windings 420A. Apower source in the form of a combustion power train 440 may drive theother set of stator windings 420B. In other embodiments, other powersources may drive stator windings 420B. Either or both of the statorwindings 420 may cooperate with rotating magnets fixed onto a driveshaft 418, to create torque and thereby turn one or more wheels 416 ofthe automobile.

The combustion power train 440 may include a combustion engine 408having a mechanical power output to drive a generator 410 having an ACpower output. The combustion power train 440 may include a rectifier 412that converts the AC output of the generator 410 to DC for transmissionover a first DC bus 424. The combustion power train 440 may include aninverter 414 to convert the DC power to AC for driving the statorwinding 420B. The electric power train 430 may include a battery 402having a direct current (DC) power output that provides DC power fortransmission over a second DC bus 422. The electric power train 430 mayinclude an inverter 404 to convert the DC power to alternating current(AC) for driving the stator winding 420A.

The architecture 400 may include a controller 450 to control theoperation of components of the propulsion system 400 in accordance withcommands or control signals received from control interface 460. Throughthe control interface 460 and the controller 450, an operator mayindependently control (i) a first power level of electric power outputat the power output of the combustion power train 440, and (ii) a secondpower level of motive power output by the traction motor 406. Thecontroller 450 may control the combustion power train 440 by controllingone or more of the battery 402, the combustion engine 408, the generator410, the rectifier 412, and the inverters 404 and 414, as indicated bythe broken lines in FIG. 4 .

While the combustion power train 440 typically has power flow in onlyone direction, the electric power train 430 has bidirectional powerflow. The rotation of the magnets attached to the shaft 418 of the motor406 may induce an AC voltage in the windings 420A, and the inverter 404may convert that AC voltage into a DC voltage to charge the battery 402over the second DC bus 422. In some embodiments, the inverter 404 may beimplemented as a four-quadrant inverter or a similar inverter to enablethis bidirectional operation.

In some embodiments, the number of turns may differ between the two setsof stator windings 420A,B. These embodiments may allow the differentpower trains 430, 440 to operate at different voltages, and may provideadvantages in controlling the charging of the battery 402 from the motor406.

FIG. 5 is a flowchart illustrating a process 500 for controlling apropulsion system of a hybrid electric vehicle according to someembodiments of the disclosed technologies. The elements of the process500 are presented in one arrangement. However, it should be understoodthat one or more elements of the process may be performed in a differentorder, in parallel, omitted entirely, and the like. Furthermore, theprocess 500 may include other elements in addition to those presented.For example, the process 500 may include error-handling functions ifexceptions occur, and the like.

Referring to FIG. 5 , the process 500 may include, responsive toreceiving signals from a control interface of a hybrid electric vehicle,independently controlling: (i) a first power level of electric poweroutput at a direct current (DC) power output of a power source of thehybrid electric vehicle, the power source electrically coupled by afirst inverter to first stator windings of a traction motor of thehybrid electric vehicle, the power source comprising a generator, and(ii) a second power level of motive power output by the traction motor,at 502. In the example of FIG. 3 , the signals may be generated by thecontrol interface 360, and in response to the signals, the controller350 may control the combustion power train 340 and governor 326 asdescribed above. In the example of FIG. 4 , the signals may be generatedby the control interface 460, and in response to the signals, thecontroller 450 may control the combustion power train 440 as describedabove.

Referring again to FIG. 5 , the process 500 may include, responsive toreceiving a signal to set the second power level at less than a fullcapacity of the traction motor, causing a power difference between thefirst power level and the second power level to be provided from secondstator windings of the traction motor through a second inverter to abattery of the hybrid electric vehicle, at 504. In the example of FIG. 3, the power is provided from the stator windings 320A to the battery 302through the inverter 304. In the example of FIG. 4 , the power isprovided from the stator windings 420A to the battery 402 through theinverter 404.

Referring again to FIG. 5 , the process 500 may include, responsive tothe power difference between the first power level and the second powerlevel exceeding a capacity of the battery to absorb power, reducing thefirst power level of electric power output at the power output of agenerator of the hybrid electric vehicle, at 506. In the example of FIG.3 , the power may be reduced by controlling the combustion engine 308and/or the generator 310. In the example of FIG. 4 , the power may bereduced by controlling the combustion engine 408 and/or the generator410.

FIG. 6 depicts a block diagram of an example computer system 600 inwhich embodiments described herein may be implemented. The computersystem 600 includes a bus 602 or other communication mechanism forcommunicating information, one or more hardware processors 604 coupledwith bus 602 for processing information. Hardware processor(s) 604 maybe, for example, one or more general purpose microprocessors.

The computer system 600 also includes a main memory 606, such as arandom access memory (RAM), cache and/or other dynamic storage devices,coupled to bus 602 for storing information and instructions to beexecuted by processor 604. Main memory 606 also may be used for storingtemporary variables or other intermediate information during executionof instructions to be executed by processor 604. Such instructions, whenstored in storage media accessible to processor 604, render computersystem 600 into a special-purpose machine that is customized to performthe operations specified in the instructions.

The computer system 600 further includes a read only memory (ROM) 608 orother static storage device coupled to bus 602 for storing staticinformation and instructions for processor 604. A storage device 610,such as a magnetic disk, optical disk, or USB thumb drive (Flash drive),etc., is provided and coupled to bus 602 for storing information andinstructions.

The computer system 600 may be coupled via bus 602 to a display 612,such as a liquid crystal display (LCD) (or touch screen), for displayinginformation to a computer user. An input device 614, includingalphanumeric and other keys, is coupled to bus 602 for communicatinginformation and command selections to processor 604. Another type ofuser input device is cursor control 616, such as a mouse, a trackball,or cursor direction keys for communicating direction information andcommand selections to processor 604 and for controlling cursor movementon display 612. In some embodiments, the same direction information andcommand selections as cursor control may be implemented via receivingtouches on a touch screen without a cursor.

The computing system 600 may include a user interface module toimplement a GUI that may be stored in a mass storage device asexecutable software codes that are executed by the computing device(s).This and other modules may include, by way of example, components, suchas software components, object-oriented software components, classcomponents and task components, processes, functions, attributes,procedures, subroutines, segments of program code, drivers, firmware,microcode, circuitry, data, databases, data structures, tables, arrays,and variables.

In general, the word “component,” “engine,” “system,” “database,” datastore,” and the like, as used herein, can refer to logic embodied inhardware or firmware, or to a collection of software instructions,possibly having entry and exit points, written in a programminglanguage, such as, for example, Java, C or C++. A software component maybe compiled and linked into an executable program, installed in adynamic link library, or may be written in an interpreted programminglanguage such as, for example, BASIC, Perl, or Python. It will beappreciated that software components may be callable from othercomponents or from themselves, and/or may be invoked in response todetected events or interrupts. Software components configured forexecution on computing devices may be provided on a computer readablemedium, such as a compact disc, digital video disc, flash drive,magnetic disc, or any other tangible medium, or as a digital download(and may be originally stored in a compressed or installable format thatrequires installation, decompression or decryption prior to execution).Such software code may be stored, partially or fully, on a memory deviceof the executing computing device, for execution by the computingdevice. Software instructions may be embedded in firmware, such as anEPROM. It will be further appreciated that hardware components may becomprised of connected logic units, such as gates and flip-flops, and/ormay be comprised of programmable units, such as programmable gate arraysor processors.

The computer system 600 may implement the techniques described hereinusing customized hard-wired logic, one or more ASICs or FPGAs, firmwareand/or program logic which in combination with the computer systemcauses or programs computer system 600 to be a special-purpose machine.According to one embodiment, the techniques herein are performed bycomputer system 600 in response to processor(s) 604 executing one ormore sequences of one or more instructions contained in main memory 606.Such instructions may be read into main memory 606 from another storagemedium, such as storage device 610. Execution of the sequences ofinstructions contained in main memory 606 causes processor(s) 604 toperform the process steps described herein. In alternative embodiments,hard-wired circuitry may be used in place of or in combination withsoftware instructions.

The term “non-transitory media,” and similar terms, as used hereinrefers to any media that store data and/or instructions that cause amachine to operate in a specific fashion. Such non-transitory media maycomprise non-volatile media and/or volatile media. Non-volatile mediaincludes, for example, optical or magnetic disks, such as storage device610. Volatile media includes dynamic memory, such as main memory 606.Common forms of non-transitory media include, for example, a floppydisk, a flexible disk, hard disk, solid state drive, magnetic tape, orany other magnetic data storage medium, a CD-ROM, any other optical datastorage medium, any physical medium with patterns of holes, a RAM, aPROM, and EPROM, a FLASH-EPROM, NVRAM, any other memory chip orcartridge, and networked versions of the same.

Non-transitory media is distinct from but may be used in conjunctionwith transmission media. Transmission media participates in transferringinformation between non-transitory media. For example, transmissionmedia includes coaxial cables, copper wire and fiber optics, includingthe wires that comprise bus 602. Transmission media can also take theform of acoustic or light waves, such as those generated duringradio-wave and infra-red data communications.

The computer system 600 also includes a communication interface 618coupled to bus 602. Network interface 618 provides a two-way datacommunication coupling to one or more network links that are connectedto one or more local networks. For example, communication interface 618may be an integrated services digital network (ISDN) card, cable modem,satellite modem, or a modem to provide a data communication connectionto a corresponding type of telephone line. As another example, networkinterface 618 may be a local area network (LAN) card to provide a datacommunication connection to a compatible LAN (or a WAN component tocommunicate with a WAN). Wireless links may also be implemented. In anysuch implementation, network interface 618 sends and receiveselectrical, electromagnetic or optical signals that carry digital datastreams representing various types of information.

A network link typically provides data communication through one or morenetworks to other data devices. For example, a network link may providea connection through local network to a host computer or to dataequipment operated by an Internet Service Provider (ISP). The ISP inturn provides data communication services through the world wide packetdata communication network now commonly referred to as the “Internet.”Local network and Internet both use electrical, electromagnetic oroptical signals that carry digital data streams. The signals through thevarious networks and the signals on network link and throughcommunication interface 618, which carry the digital data to and fromcomputer system 600, are example forms of transmission media.

The computer system 600 can send messages and receive data, includingprogram code, through the network(s), network link and communicationinterface 618. In the Internet example, a server might transmit arequested code for an application program through the Internet, the ISP,the local network and the communication interface 618.

The received code may be executed by processor 604 as it is received,and/or stored in storage device 610, or other non-volatile storage forlater execution.

Each of the processes, methods, and algorithms described in thepreceding sections may be embodied in, and fully or partially automatedby, code components executed by one or more computer systems or computerprocessors comprising computer hardware. The one or more computersystems or computer processors may also operate to support performanceof the relevant operations in a “cloud computing” environment or as a“software as a service” (SaaS). The processes and algorithms may beimplemented partially or wholly in application-specific circuitry. Thevarious features and processes described above may be used independentlyof one another, or may be combined in various ways. Differentcombinations and sub-combinations are intended to fall within the scopeof this disclosure, and certain method or process blocks may be omittedin some implementations. The methods and processes described herein arealso not limited to any particular sequence, and the blocks or statesrelating thereto can be performed in other sequences that areappropriate, or may be performed in parallel, or in some other manner.Blocks or states may be added to or removed from the disclosed exampleembodiments. The performance of certain of the operations or processesmay be distributed among computer systems or computers processors, notonly residing within a single machine, but deployed across a number ofmachines.

As used herein, a circuit might be implemented utilizing any form ofhardware, or a combination of hardware and software. For example, one ormore processors, controllers, ASICs, PLAs, PALs, CPLDs, FPGAs, logicalcomponents, software routines or other mechanisms might be implementedto make up a circuit. In implementation, the various circuits describedherein might be implemented as discrete circuits or the functions andfeatures described can be shared in part or in total among one or morecircuits. Even though various features or elements of functionality maybe individually described or claimed as separate circuits, thesefeatures and functionality can be shared among one or more commoncircuits, and such description shall not require or imply that separatecircuits are required to implement such features or functionality. Wherea circuit is implemented in whole or in part using software, suchsoftware can be implemented to operate with a computing or processingsystem capable of carrying out the functionality described with respectthereto, such as computer system 600.

As used herein, the term “or” may be construed in either an inclusive orexclusive sense. Moreover, the description of resources, operations, orstructures in the singular shall not be read to exclude the plural.Conditional language, such as, among others, “can,” “could,” “might,” or“may,” unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements and/or steps.

Terms and phrases used in this document, and variations thereof, unlessotherwise expressly stated, should be construed as open ended as opposedto limiting. Adjectives such as “conventional,” “traditional,” “normal,”“standard,” “known,” and terms of similar meaning should not beconstrued as limiting the item described to a given time period or to anitem available as of a given time, but instead should be read toencompass conventional, traditional, normal, or standard technologiesthat may be available or known now or at any time in the future. Thepresence of broadening words and phrases such as “one or more,” “atleast,” “but not limited to” or other like phrases in some instancesshall not be read to mean that the narrower case is intended or requiredin instances where such broadening phrases may be absent.

What is claimed is:
 1. An propulsion system for a hybrid electricvehicle, comprising: a traction motor having first stator windings andsecond stator windings; a power source having a first direct current(DC) power output, the power source comprising a generator; a batteryhaving a second DC power output; a first inverter electrically coupledbetween the first DC power output of the power source and the firststator windings; a second inverter electrically coupled between thesecond DC power output of the battery and the second stator windings;and a controller configured to independently control: (i) a first powerlevel of electric power output at the power output of the power source,and (ii) a second power level of motive power output by the tractionmotor; wherein responsive to receiving a signal to set the second powerlevel at less than a full capacity of the traction motor, the controlleris configured to provide a power difference between the first powerlevel and the second power level from the second stator windings throughthe second inverter to the battery; and wherein responsive to the powerdifference between the first power level and the second power levelexceeding a capacity of the battery to absorb power, the controller isconfigured to reduce the first power level of electric power output atthe power output of the generator.
 2. The propulsion system for a hybridelectric vehicle of claim 1, further comprising: a control interface,wherein the controller is further configured to independently controlthe first power level and the second power level responsive to signalsreceived from the control interface.
 3. The propulsion system for ahybrid electric vehicle of claim 1, wherein: the second inverter is afour-quadrant inverter.
 4. The propulsion system for a hybrid electricvehicle of claim 1, wherein the power source comprises: an engine havinga mechanical power output, wherein the generator has (i) an electricalpower output and (ii) a mechanical power input, the mechanical powerinput mechanically coupled to the mechanical power output of the engine;and a rectifier having (i) an electrical power input electricallycoupled to the electrical power output of the generator and (ii) anelectrical power output electrically coupled to the DC power output ofthe power source.
 5. The propulsion system for a hybrid electric vehicleof claim 1, wherein: the engine is a combustion engine.
 6. Thepropulsion system for a hybrid electric vehicle of claim 1, wherein: thehybrid electric vehicle is an aircraft.
 7. The propulsion system for ahybrid electric vehicle of claim 2, further comprising: a variable-pitchpropeller; and a governor configured to control a pitch of thevariable-pitch propeller; wherein the controller is further configuredto control the governor responsive to signals received from the controlinterface.
 8. The propulsion system for a hybrid electric vehicle ofclaim 1, wherein: the hybrid electric vehicle is an automobile.
 9. Apropulsion system for a hybrid electric vehicle, further comprising: atraction motor having first stator windings and second stator windings;a power source having a first direct current (DC) power output, thepower source comprising a generator; a battery having a second DC poweroutput; a first inverter electrically coupled between the first DC poweroutput of the power source and the first stator windings; a secondinverter electrically coupled between the second DC power output of thebattery and the second stator windings; one or more hardware processors;and a non-transitory machine-readable storage medium encoded withinstructions executable by the hardware processor to perform operationscomprising: responsive to receiving signals from a control interface,independently controlling: (i) a first power level of electric poweroutput at the power output of the power source, and (ii) a second powerlevel of motive power output by the traction motor; responsive toreceiving a signal to set the second power level at less than a fullcapacity of the traction motor, providing a power difference between thefirst power level and the second power level from the second statorwindings through the second inverter to the battery; and responsive tothe power difference between the first power level and the second powerlevel exceeding a capacity of the battery to absorb power, reducing thefirst power level of electric power output at the power output of thegenerator.
 10. The propulsion system for a hybrid electric vehicle ofclaim 9, further comprising: a control interface, wherein the controlleris further configured to independently control the first power level andthe second power level responsive to signals received from the controlinterface.
 11. The propulsion system for a hybrid electric vehicle ofclaim 9, wherein: the second inverter is a four-quadrant inverter. 12.The propulsion system for a hybrid electric vehicle of claim 9, whereinthe power source comprises: an engine having a mechanical power output,wherein the generator has (i) an electrical power output and (ii) amechanical power input, the mechanical power input mechanically coupledto the mechanical power output of the engine; and a rectifier having (i)an electrical power input electrically coupled to the electrical poweroutput of the generator and (ii) an electrical power output electricallycoupled to the DC power output of the power source.
 13. The propulsionsystem for a hybrid electric vehicle of claim 9, wherein: the engine isa combustion engine.
 14. The propulsion system for a hybrid electricvehicle of claim 9, wherein: the hybrid electric vehicle is an aircraft.15. The propulsion system for a hybrid electric vehicle of claim 10,further comprising: a variable-pitch propeller; and a governorconfigured to control a pitch of the variable-pitch propeller; whereinthe controller is further configured to control the governor responsiveto signals received from the control interface.
 16. The propulsionsystem for a hybrid electric vehicle of claim 9, wherein: the hybridelectric vehicle is an automobile.
 17. A non-transitory machine-readablestorage medium encoded with instructions executable by a hardwareprocessor of a computing component, the machine-readable storage mediumcomprising instructions to cause the hardware processor to performoperations comprising: responsive to receiving signals from a controlinterface of a hybrid electric vehicle, independently controlling: (i) afirst power level of electric power output at a direct current (DC)power output of a power source of the hybrid electric vehicle, the powersource electrically coupled by a first inverter to first stator windingsof a traction motor of the hybrid electric vehicle, the power sourcecomprising a generator, and (ii) a second power level of motive poweroutput by the traction motor; responsive to receiving a signal to setthe second power level at less than a full capacity of the tractionmotor, providing a power difference between the first power level andthe second power level from second stator windings of the traction motorthrough a second inverter to a battery of the hybrid electric vehicle;and responsive to the power difference between the first power level andthe second power level exceeding a capacity of the battery to absorbpower, reducing the first power level of electric power output at thepower output of a generator of the hybrid electric vehicle.
 18. Thenon-transitory machine-readable storage medium of claim 17, wherein: thehybrid electric vehicle is an aircraft.
 19. The non-transitorymachine-readable storage medium of claim 18, wherein the operationsfurther comprise: responsive to the signals received from the controlinterface, controlling a governor configured to control a pitch of avariable-pitch propeller of the aircraft.
 20. The non-transitorymachine-readable storage medium of claim 17, wherein: the hybridelectric vehicle is an automobile.